Reply to “How to diagnose Mycoplasma pneumoniae etiology in a child with pneumonia”

Excerpt

About the question raised by Korppi [4], the diagnostic criteria for Mycoplasma pneumoniae pneumonia (MPP) were diverse. Several diagnostic methods have been used to diagnose M. pneumoniae infection, including M. pneumoniae isolation, serologic testing, and molecular-based detection assays [7]. Each of these methods had limitations including serologic testing. However, serologic testing for M. pneumoniae infection was accepted widely. In Liu’s study [5], the diagnosis of active infection with M. pneumoniae was based on an at least fourfold mycoplasma particle agglutinin titer elevation in paired sera or the presence of anti-mycoplasma IgM above the cutoff value. Serological tests were performed in a total of 140 children and paired sera were obtained from only 41 of them. In Eun’s study [1], a fourfold or greater rise in the antibody titers and/or a single titer >1:640 were considered diagnostic of M. pneumoniae infections using indirect particle agglutination test. In this paper, no figure was exactly indicated how many children were only diagnosed based on single serology. Other studies [2, 3, 6, 10] also included single-point serology as a diagnostic criteria. Yamazaki et al. [9] concluded that in unpaired sera, a PA antibody titer of 1:80 or 1:160 is useful for the serological diagnosis of M. pneumonia infection among children with LRTI. …